| T O P I C R E V I E W |
| Rogers6775 |
Posted - 15 May 2007 : 11:57:23
After performing a "transfer to PCB" and using Prorouter to route a board, there were 5 or 6 nets that are on the schematic but that did not appear on the PCB. The router showed 100% completion. with no nets being unrouted.
Two were flagged as single pin nets by the design status report. The others I found as a result of running the Integrity check.
At no point had I actually edited any tracks, so I know that they were not deleted by me.
What I think may have happened to cause this is that after initially placing the components on the board, I moved some (perhaps all, I don't recall) of the components associated with the dropped nets to other locations to improve the layout.
This was all done prior to routing the board, so I know it was NOT caused by deleting a section of a track.
What's going on here? Somehow the connectivity information is being corrupted prior to even routing the board.
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| 3 L A T E S T R E P L I E S (Newest First) |
| Peter Johnson |
Posted - 16 May 2007 : 06:57:12
Firstly, thank you, as you've obviously done much of the diagnostic work on this issue yourself.
The problem with cut and paste is that it's moving data outside the program. What's happenning is that the data is placed on the clipboard when copied or cut, and when pasted, it's treated as new items being placed by Easy-PC.
My understanding of the process is that the component and net numbers are recorded on the clipboard, but when pasted, the conflict checking code is triggered. The component numbers aren't affected, as they're obviously not duplicated, but there can be issues with nets, as the parts cut from the design aren't necessarily no longer present. (They may just have been split).
I believe that the connections you are losing are those that only cross the boundary of the items you cut and pasted, and aren't going anywhere else. Because these are being left as single pin nets when you cut, they're being tidied up, with the result that they're not present when the block is pasted back.
It's one of those subtle 'Catch 22' interaction effects. I'll report it to the design team in case anything can be done to make it less likely. |
| Rogers6775 |
Posted - 15 May 2007 : 16:58:35
Re: Dropped nets....
I have discovered, much to my chagrin, that the problem I am having with dropped nets was caused by cutting and pasting a section of placed parts into another area of the board to accomplish the "move".
In Easy PC, this causes the connections to be "lost".
That was the only way to move a group of components in my last PCB software.
If I use the move technique outlined in the manual, I don't lose connectivity.
It still seems somewhat strange that this happens, since you are asked to confirm whether or not you wish to merge the new nets with the old nets. This gives the impression that they are indeed joined, which is not the case in a cut and paste.
Is cut and paste supposed to work this way, or is there some fundamental thing I am overlooking?
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| Rogers6775 |
Posted - 15 May 2007 : 12:51:17
Something I noticed after posting the above is that the connections that were dropped in the routed PCB still showed as connections (ratsnest) in the UNROUTED PCB.
In other words, after placement on the PCB (and after moving some components) the "ratsnest" still showed these pins as connected, although the Prorouter did not route them and did not seem to be aware of the connections as it did not report them as unrouted connections.
Maybe this is a clue as to what the problem is.
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